Mainwaring was described during the trial as having a "perverted interest in young boys." The offences took place during the 1970s, when he worked for the BBC, and the 1980s and were carried out over a sustained period of years.

The acts centred on three young boys who were aged 11 and 12 at the time and continued into their early teens.

All were described as keen musicians at the time who were taken in by Mainwaring who told them about his work on TV and radio.

Judge Farmer, passing sentence, also ordered that Mainwaring be put on the sexual offenders register for 10 years after his release from prison.